Vitamins & Nutrients

Transferrin Saturation % Blood Test

Transferrin saturation is a calculated value that estimates the proportion of transferrin molecules carrying iron. Under normal conditions, about one-third of transferrin's binding capacity is used, with two-thirds held in reserve. A result that is significantly below or above this level can indicate iron deficiency or iron overload respectively. This marker is an essential part of a comprehensive iron panel and is derived from serum iron and transferrin (or TIBC) results.

Why Test Transferrin Saturation %?

Testing transferrin saturation is important for anyone at risk of iron imbalance. This includes people with diets low in iron, meat or seafood, those with heavy periods, pregnant women, endurance athletes, and individuals with a family history of haemochromatosis. It helps identify risk factors early and monitor changes during dietary adjustments, supplementation or treatment.

What Do High Transferrin Saturation % Levels Mean?

High transferrin saturation is most commonly caused by hereditary haemochromatosis, a condition in which the body absorbs too much iron from food. It can also result from iron poisoning or excessive supplementation. If left unmanaged, iron overload can damage the liver, heart and other organs.

What Do Low Transferrin Saturation % Levels Mean?

Low transferrin saturation is most often a sign of iron deficiency anaemia. The body has insufficient iron to saturate its transport proteins. This is typically seen alongside low ferritin and low serum iron. Causes include inadequate dietary intake, malabsorption and chronic blood loss.

Symptoms to Watch For

  • Fatigue and weakness
  • Pale skin
  • Dizziness
  • Shortness of breath
  • Joint pain and abdominal pain (in iron overload)
  • Skin darkening (in haemochromatosis)

Who Should Get Tested?

  • People with diets low in iron or animal products
  • Women with heavy menstrual periods or who are pregnant
  • Endurance athletes
  • Those with a personal or family history of haemochromatosis
  • Anyone with unexplained fatigue, pallor or joint pain
  • People already testing ferritin or serum iron who want a complete iron assessment

How to Prepare for Your Test

Avoid iron supplements for 24 hours before the test. Bring valid ID to the lab.

Order Your Blood Test

Test your Transferrin Saturation % levels with an accredited Swedish laboratory. Results within days, reviewed by Wellth.

Transferrin Saturation →

Frequently Asked Questions

What is a normal transferrin saturation?
Normal transferrin saturation is typically between 20 % and 50 %. Values below 20 % may suggest iron deficiency, while values above 50 % may indicate iron overload.
How is transferrin saturation calculated?
It is calculated by dividing serum iron by total iron-binding capacity (TIBC) or transferrin, then multiplying by 100 to get a percentage.
Can recent blood transfusions affect the result?
Yes. Blood transfusions, iron injections and recent iron supplementation can all influence the results of iron tests, including transferrin saturation.
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Wellth

Our content is written and reviewed by Wellth, and fact-checked against peer-reviewed research and current Swedish clinical guidelines.

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Medical Disclaimer

The information on this page is provided for informational purposes only and does not constitute professional medical advice, diagnosis, or treatment. Wellth provides health information and testing services but is not a substitute for clinical care. Always consult a qualified healthcare provider if you have questions about a medical condition. If you are experiencing severe or urgent symptoms, contact your doctor or call 1177 Vårdguiden. Blood test results should be interpreted by a qualified healthcare professional in the context of your complete medical history.